Apparatus for continuously conditioning air



April 140, 1962 N. WEINSTEIN 3,028,734

APPARATUS FOR CONTINUOUSLY CONDITIONING AIR Filed. March 6, 1961 2SheetsfSheet l 8/5 1 625 535 w 203 845 20/ 204 23 II/S POWER 25/ 254 26/fiUPPL) 264 //5 V ac 252 253 263 262 INVENTOR.

[Va/man Weinsfe/n April 10, 1962 N. WEINSTEIN APPARATUS FOR CONTINUOUSLYCONDITIONING AIR Filed March 6, 1961 2 Sheets-Sheet 2 NE Mm vm INV ENTOR. Worm/2 We/hsfaw BY United States Patent 3,028,734 APPARATUS FORCONTINUOUSLY C'ONDITIGNING AIR Norman Weinstein, 3360 N. Lake ShoreDrive, Chicago, Ill. Filed Mar. 6, 1961, Ser. No. 93,607 Claims. (Cl.62-140) The present invention relates to apparatus for continuouslyconditioning air.

It is the general object of the invention to provide apparatus forcontinuously conditioning air that requires no shut-down of theprincipal component elements of the apparatus and that requires nosubstantial duplexing of the principal component elements of theapparatus.

Another object of the invention is to provide continuously operating airconditioning apparatus of the character noted, in which the air isconditioned to a temperature at, or below, the frost point.

Another object of the invention is to provide in air conditioningapparatus of the character noted, an improved sequence of cooling andreheating stages so that the temperature of the air may be reduced withsubstantial dehumidification thereof in a simple and economical mannerinvolving relatively small compact equipment.

Another object of the invention is to provide contin' ously operativeapparatus for conditioning air by dehumidifying it and by subsequentlyreheating it so that the air is conditioned to a uniform moisturecontent and to a uniform temperature.

A further object of the invention is to provide air conditioningapparatus of improved and simplified construction and arrangement andwherein the conditioned air is of uniform moisture content and ofuniform dry bulb temperature.

A further object of the invention is to provide apparatus of thecharacter described that is capable of conditioning air at apredetermined rate to a substantially constant condition and thatrequires substantially less refrigeration capacity than has beenemployed heretofore.

Further features of the invention pertain to the particular arrangementof the elements of the air conditioning apparatus, whereby theabove-outlined and additional operating features thereof are attained.

The invention, both as to its organization and method of operation,together with further objects and advantages thereof, will best beunderstood by reference to the following specification, taken inconnection with the accon1 partying drawings, in which:

FIGS. 1 and 2, taken together, illustrate diagrammatically airconditioning apparatus embodying the present invention; and

FIG. 3 illustrates diagrammatically the electric control circuit that isincorporated in the apparatus of FIGS. 1 and 2.

In order to form a unified diagram, FIG. 2 should be arranged in ahorizontal position, and FIG. 1 shouldbe arranged in a vertical positionabove the top central portion of FIG. 2.

Referring now toFlGS. 1 and 2 of the drawings, the continuous airconditioning apparatus there illustrated and embodying the features ofthe present invention comprises a first conduit 11, a second conduit 12,a third conduit 13, a first elongated housing 21, a first two-positionvalve mechanism 31 for selectively connecting the first housing 21 inopposite directions between the first conduit 11 and the second conduit12, and a second housing 41 directly connected between the secondconduit 12 and the third conduit 13. In the arrangement, the housing 21may be arranged in any suitable position, and has been illustrated asbeing in the horizontal position as a matter of convenience, the housing21 being supported by a plu- 3,028,734 I Patented Apr. 1 1962 rality ofupstandingfeet or columns 22. The second housing may be arranged in anysuitable position, and has been illustrated as being in the verticalposition as a matter ofconvenience, the housing 41 being supported by aplurality of upstanding feet or columns 42. The housing 21 includes afirst port 23 disposed at the righthand end thereof and a second port 24disposed .at the left-hand end thereof, the two ports 23 and24respectively communicating with two transfer conduits 15 and 16. Also,in the arrangement, the housing 41 includes a first port 43 disposed atthe bottom thereof and a second port 44 disposed at the top thereof, thetwo ports 43 and 44 respectively communicating with the second conduit12 and the third conduit 13. Y

I Ambient air to be conditioned is supplied to the first conduit 11 byan associated blower 51 that is provided with a casing having an inletpipe 52 and an outlet pipe 53, the inlet pipe 52 communicating with anassociated dust filter 54 and the outlet pipe 53 communicating with thefirst conduit 11. The conditioned air from the third conduit 13 issuppiied to a missile 'crib, or the like, not shown, that requires theconditioned air. 1

The two-position valve mechanism 31 includes a-ca'sing 32 housing arotatably mounted valve element 33 supported by a rotatably operatedshaft, indicated at 34; which valve element 33 has a normal position,illustrated in FIG. 1, and an operated position disposed in theclockwise direction with respect to its normal position. The casing 32terminates the first conduit 11, the second conduit 12 and the twotransfer conduits 15 and 16. In the arrangement, when the valve element33 occupies its normal position, the first conduit 11 is connected tothe transfer conduit 15 and the second conduit 12 is connected to thetransfer conduit 16; whereby the air sup,- plied from the blower 51 tothe first conduit 11 proceeds into the transfer conduit 15 and thencethrough the housing 11 from right to left and therefrom via the transfer conduit 16 into the second conduit 12 and therefrom upwardly throughthehousing 41into the third conduit 13. On the other hand, when thevalve element 33 occupies its operated position, the first conduit 11 isconnected to the transfer conduit 16 and the second conduit 12 isconnected to the transfer conduit 15; whereby the air supplied from theblower 51 to the first conduit .11 proceeds into the transfer conduit 16and thence through the housing 21 from left to right and therefrom viathe transfer conduit 15 into the second conduit 12and therefrom upwardlythrough the housing 41 into the third con duit 13. I

The valve element 33 is selectively actuated between its normal andoperated positions by actuating mechanism 61 that is operativelyassociated with the operating shaft 34; which mechanism 61 comprises apinion 62 rigidly secured to the outer end of the operating shaft 34and-a cooperating rack 63. The rack 63 is biased toward the right by anassociated tension spring 64 and is operated toward the left by anassociated armature 65 that is provided with a cooperating operatingsolenoid 658. The right-hand position of the rack 63 is established by acooperating stop 66 and the left-hand position of the rack 63 isestablished by a cooperating stop 67. g

In the arrangement, when the solenoid 658 is deenergized, the tensionspring 64 returns the rack 63 toward the right as established by thestop 66; whereby the rack 63 rotates the pinion 62 in thecounterclockwise direction for the purpose of actuating through theoperating shaft 34 the valve element 33 into its normal position, asillustrated in FIG. 1. On the other hand, when the solenoid 655 isenergized, the armature 65 is attracted moving the rack 63 toward theleft as established by the stop 67'; whereby the rack 63 rotates thepinion 62 in the'cloc kwise direction for the purpose of actuatingthrough the operating shaft 34 the valve element 33 into its operatedposition.

A primary cooling coil 71 is arranged in the intermediate portion of thehousing 21 and provided with first and second fixtures 72 and 73 at theopposite ends thereof; and a heating coil 74 is arranged in the housing41 and provided with first and second fixtures 75 and 76 at the oppositeends thereof. The primary cooling coil 71 and the heating coil 74 arearranged in a local heat-exchange circuit, also including a circulatingpump 77 and a second two-position valve mechanism, indicated generallyat 80. More specifically, the two-position valve mechanism 80 comprisesfour individual valves 81, 82, 83 and 84 respectively provided withoperating solenoids 818, 828, 838 and 845. In the arrangement, thevalves 81 and 82 are normally biased into their open positions and arerespectively operated into their closed positions in response toenergization of the corresponding solenoids 81S and 828, while thevalves 83 and 84 are normally biased into their closed positions and arerespectively operated into their open positions in response toenergization of the corresponding solenoids 83S and 843. Accordingly,the two-position valve mechanism 80 occupies its normal position, asindicated in FIG. 2, when each of the solenoids 818, 825, 835 and 845 isdeenergized; while the twoposition valve mechanism 80 occupies itsoperated position, when each of the solenoids 81S, 82S, 83S and 848 isenergized.

The local heat-exchange circuit mentioned includes a quantity of coolantwhich may suitably comprise a brine solution; and specifically, thebrine solution may comprise an aqueous solution of calcium chloride. Inthe arrangement of the local heat-exchange circuit, the fixtures 72 and73 provided at the opposite ends of the primary cooling coil 71 arerespectively connected to two pipes 91 and 92; the fixtures 75 and 76provided at the opposite ends of the heating coil 74 are respectivelyconnected to two pipes 93 and 94; a pipe 95 is connected to the inlet ofthe circulating pump 77; and the outlet of the circulating pump 77 isconnected to the pipe 93. A bridging pipe 96 is connected between thepipes 91 and 94; a bridging pipe 97 is connected between the pipes 92and 93; a cross-over pipe 98 is connected between the pipes 91 and 95;and a cross-over pipe 99 is connected between the pipes 92 and 94. Inthe arrangement, the valves 81 and 82 are respectively positioned in thebridging pipes 96 and 97, and the valves 83 and 84 are respectivelypositioned in the cross-over pipes 98 and 99.

When the two-position valve mechanism 80 occupies its normal position,the brine is circulated from the pump 77 via the pipe 93 and the fixture75 through the heating coil 74 and thence via the fixture 76 into thepipe 94; from the pipe 94, the brine proceeds via the bridging pipe 96,the pipe 91 and the fixture 72 through the primary cooling coil 71 andtherefrom via the fixture 73 into the pipe 92; and from the pipe 92, thebrine proceeds through the bridging pipe 97 into the pipe 95 and thusback to the inlet of the circulating pump 77 to complete the cycle. Onthe other hand, when the two-position valve mechanism 80 occupies itsoperated position, the brine is circulated from the pump 77 via the pipe93 and the fixture 75 through the heating coil 74 and thence via thefixture 76 into the pipe 94; from the pipe 94, the brine proceeds viathe cross-over pipe 99, the pipe 92 of the fixture 73 through theprimary cooling coil 71 and therefrom via the fixture 72 into the pipe91; and from the pipe 91, the brine proceeds through the cross-over pipe98 into the pipe 95 and thus back to the inlet of the circulating pump77 to complete the cycle. Accordingly, it will be understood that whenthe two-position valve mechanism 80 occupies its normal position, thebrine is circulated through the primary cooling coil 71 from left toright; on the other hand, when the two-position valve mechanism occupiesits operated position, the brine is circulated through the primarycooling coil 71 from right to left. Of course, the operation of thelocal heat-exchange circuit is effective to transfer heat from theprimary cooling coil 71 to the heating coil 74, for a purpose more fullyexplained hereinafter.

Further, the apparatus 10 comprises a first secondary cooling coil 101arranged in the housing 21 and disposed between the second port 24therein and the adjacent lefthand side of the primary cooling coil 71,and a second secondary cooling coil 102 arranged in the housing 21 anddisposed between the first port 23 therein and the adjacent right-handside of the primary cooling coil 71. Also, a third two-position valvemechanism, indicated generally at in FIG. 2 is provided for the purposeof selectively controlling the supply of a second coolant to the twosecondary cooling coils 101 and 102. More specifically, the two-positionvalve mechanism 110 comprises two individual valves 111 and 112respectively provided with operating solenoids 1118 and 1125. In thearrangement, the valve 111 is normally biased into its open position andis operated into its closed position in response to energization of thesolenoid 111$, while the valve 112 is normally biased into its closedposition and is operated into its open position in response toenergization of the solenoid 1128. Accordingly, the twoposition valvemechanism 110 occupies its normal position, as indicated in FIG. 2, wheneach of the solenoids 1118 and 1128 is deenergized; while thetwo-position valve mechanism 110 occupies its operated position, wheneach of the solenoids 1118 and 1128 is energized.

Further, the apparatus 10 comprises a heat sump containing a quantity ofbrine 121 of the character previously described; and operativelyassociated therewith is a refrigerating machine that includes acompressor 131, an associated condenser 132, a cooperating expansionvalve 133, and an associated evaporator 134, the evaporator 134 beingsubmerged in the brine 121 contained in the heat sump 120. Of course,the refrigerating machine 130 contains a suitable refrigerant that iscompressed in the gaseous stage in the compressor 131 and supplied tothe condenser 132. In the condenser 132, the compressed gaseousrefrigerant is liquified, and the liquified refrigerant is expanded bythe expansion valve 133 into the evaporator 134. Ultimately, theexpanded gaseous refrigerant is returned from the evaporator 134 back tothe compressor 131 to complete the cycle. Of course, the operation ofthe refrigerating machine 130 effects cooling of the brine 121 containedin the heat sump 120, the heat mentioned being transferred from theevaporator 134 to the condenser 132 and discharged therefrom to theexterior in any suitable manner.

A second local brine circuit is provided that includes a heat exchangecoil 141, a circulating pump 142, a regulating valve 143 and twocirculating pipes 144 and 145. The circulating pipe 144 is commonlyconnected to the two valves 111 and 112 that are respectively connectedto the inlets of the two secondary cooling coils 101 and 102; while theoutlet of the two secondary cooling coils 101 and 102 are commonlyconnected to the circulating pipe 145. Operation of the circulating pump142 withdraws brine from the circulating pipe and forces the samethrough the heat exchange coil 141 and therefrom the brine, aftercooling thereof in the heat sump 120, is returned via the regulatingvalve 143 back to the circulating pipe 144, the heat exchange coil 141also being submerged in the brine 121 contained in the heat sump 120.One of the valves 111 or 112 occupies its open position; whereby thebrine is circulated from the circulating pipe 144 through thecorresponding one of the secondary cooling coils 101 or 102 and then isreturned to the circulating pipe 145 to complete the circuit. Of course,it will be understood that the operation of the circulating pump 142effects cooling of the one of the secondary cooling coils 101 and 102through which the brine is circulated between the circulating pipes 144and 145. More specifically, when the two-position valve mechanism 119occupies its normal positions, indicated in FIG. 2, the brine iscirculated through the secondary cooling coil 101; on the other hand,when the two-position valve mechanism 110 occupies its operatedposition, the brine is circulated through the secondary cooling coil1412.

The regulating valve 143 is of the modulating or throttling type and iscontrolled by a wet bulb device 46 arranged in the housing 41 adjacentto the port 43 therein, the bulb device 46 being operatively connectedto the regulating valve 143 via an associated tube 147. In thearrangement, the bulb device 46 is responsive to the dew point of theair proceeding from the second conduit 12 into the bottom of the housing41 and is operative to effect throttling of the regulating valve 143 andthe consequent control of the rate at which the brine is circulated bythe circulating pump 142 between the heat exchange coil 141 and theoperating one of the secondary cooling coils 101 or 1%.

Further, the appartus comprises an electric control circuit 200,illustrated in FIG. 3, that includes the seven solenoids 658, 818, 828,835, 848, 1118 and 1128 that have been previously described. Further,the control circuit 2% includes a source of electric power supply,including two conductors 2t1 and 2ti2, that may be of 115-volts,single-phase, A.-C. In the arrangement, the conductor 2% may begrounded, while the conductor 202 is ungrounded, and the two conductors201 and 2&2 are respectively connected by two fuses 2G3 and 2534 to twoconductors 295 and 296 that are terminated by a manually operablecontrol switch 210. When the control switch 219 occupies its closedposition, the conductors 295 and 2% are respectively connected to twoconductors 211 and 212 across which a timer motor 213 is connected. Thetimer motor 213 may be of any suitable type, but preferably comprises asynchronous motor of the Telechron type that includes an operating shaft214 that is rotated upon a timed basis. The operating shaft 214 isconnected by reduction gearing 215 to an operating shaft 216; whichoperating shaft 216 is connected by a slip clutch 217 to an operatingshaft 218,. An electric control cam 219 is rigidly secured to theintermediate portion of the operating shaft 218, and the outer end ofthe operating shaft 213 carries a manually operable control knob 22%. Inthe arrangement, the relative position of the operating shaft 218 may beselectively adjusted with respect to the position of the operating shaft216 through the action of the slip clutch 217 by appropriate rotation ofthe manual knob 22%;, whereby the clock-time position of the electricalcontrol cam 219 may be selectively set with respect to the clock-timeposition of the operating shaft 216. Operatively associated with theelectric control carn 219 are a common wiper 221 and two individualcontrol wipers 222 and 223; and the electric control cam 219 may bedivided into a conducting day segment and a nonconducting night segmentcommonly cooperating with the control wipers 222 and 223.

Also, the conductor 212 is connected via a crystal diode 231 to a bus232; a load resistor 233 is connected between the bus 232 and thegrounded conductor 201; and likewise, a capacitor 234 is connectedbetween the bus .232 and the grounded conductor 291. Accordingly, whenthe control switch 210 occupies its closed position, the crystal diode231 is operative to effect rectification, with the result that a D.-C.voltage is developed across the load resistor 2133 that is fairlyconstant by virtue of the filtering action of the capacitor 234; and thebus 232 is connected to the common wiper 221. V

In the arrangement, the control wipers 222- and 223 are disposeddiametrically opposite to each other in cooperating relation with theelectric control cam 219; whereby the potential appearing upon the bus232 is applied to the control wiper 222 during the day cycle 7 6 of theelectric control cam 219, and the potential appear ing upon the bus 232is applied to the control wiper 223 during the night cycle of theelectric control cam 219. Further, the two control wipers 222 and 223are respectively connected to two conductors 241 and 242 that arerespectively terminated by two switches 243 and 244 that arerespectively governed by two frost-responsive devices, indicatedgenerally at 251 and 261. More particularly, the frost-responsive device251 includes .a bulb 252 that is directly secured to the secondarycooling coil 101, as indicated in FIG. 2; while the frost-responsivedevice 261 includes a bulb 262 that is directly secured to the bulb 252is connected via a tube 253 to an expansible bellows 254 that, in turn,is connected to the switch 2415; similarly, the bulb 262 is connectedvia a tube 263 to an expansible bellows 264 that, in turn, is connectedto the switch 244.

In the arrangement, the switch 243 normally occupies its open position,and in response to the accumulation of an undue amount of frost upon thesecondary cooling coil 191, the bulb 252 governs the bellows 257 inorder to actuate the switch 243 into its closed position, for a purposemore fully explained below. Similarly the switch 243 normally occupiesits closed position, and in response to the accumulation of an undueamount of frost upon the secondary cooling coil 102, the bulb 262governs the bellows 2 64, in order to actuate the switch 244 into itsopen position, for a purpose more fully ex:- plained below. Finally, inthe circuit arrangement, the switches 243 i and 244 commonly terminate aconductor 245; and the seven solenoids 658, 815, 325,838, 848, 1118 and1128 are commonly bridged in parallel relation across the conductors 201and 245. I

Considering now the general mode of operation of the control circuit209, and assuming that the control switch 21! occupies its closedposition, the timer motor 213 operates alternately to establish the daycycle and the night cycle of the electric control cam 219; and each ofthese cycles may conveniently comprise 12 hours of the 24-hour day.During the day cycle of the control circuit 291 the conducting segmentof the electric control cam 219 is in contact with the control wiper 222and the insulating segment of the electric control cam 219 is inengagement with the control wiper 223; whereby the potential appearingupon the conductor 232 is applied to the conductor 241 during the daycycle. On the other hand, during the night cycle of the control circuit209, the conducting segment of the electric control cam 219 is incontact with the control wiper 223 and the insulating segment of theelectric control cam 21? is in engagement I with the control wiper 222;whereby the potential appearing upon the conductor 232 is applied to theconductor 242. The presence of the potential mentioned upon theconductor 241 is normally without effect with respect to theenergization of the solenoids 653, etc.; whereas the presence of thepotentialmentioned upon the conductor 242 normally effects energization'of thesolenoids 655, etc. During the day cycle of operation of thecontrol circuit 239, in the event of an abnormal accumulation of frostupon the secondary cooling coil 1491, the device 251 responds to e'fiectclosure of the switch 243 and the consequent energization of thesolenoids 658, etc. whereby the control circuit 2% is forced into itsnight cycle operation. On the other hand, durnig the night cycle ofoperation of the control circuit 200, in the event of an abnormalaccumulation of frost upon the secondary.

cooling coil 162, the device 261 .responds to effect opening of theswitch 244 and the consequent deenergization of the solenoids 653, etc.;whereby the control circuit are deenergized, with the result that thetwo-position valve mechanisms 31, 80 and 110 occupy their normalpositions; whereby the air that is supplied by the fan 51 into the firstconduit 11 proceeds from right to left through the housing 21 and thencethrough the second conduit 12 and through the housing 41 into the thirdconduit 13. The air in passing from right to left through the housing 21first encounters the secondary cooling coil 102 and then the primarycooling coil 71 and then the secondary cooling coil 101. Also, the brineis circulated from the pump 77 through the heating coil 74 and thencethrough the primary cooling coil 71 from left to right and thence backto the circulating pump 77. Furthermore, at this time, the pump 142efiects circulation of the brine through the heat exchange coil 141 andthence through the secondary cooling coil 101 from left to right andthence back to the circulating pump 142. At this time, in the eventthere is an accumulation of frost upon the secondary cooling coil 102(resulting from the prior night cycle of operation of the apparatus thefrost mentioned is melted therefrom and is drained to the exterior ofthe housing 21 in any suitable manner, not shown. This contact of thecirculated air with the secondary cooling coil 102 effects slightcooling thereof and also possibly some increase in the relative humiditythereof; however, these effects are not substantial and it may beassumed that the air passing into the port 23 in the right-hand end ofthe housing 21 is already at the ambient temperature and fullysaturated. The air next encounters the primary cooling coil 71, aspreviously noted, whereby both sensible heat and latent heat are removedtherefrom, with the consequent reduction of the temperature of thecirculated air and of the dew point thereof. The air next encounters theprimary cooling coil 101, as previously noted, whereby both sensibleheat and latent heat are removed therefrom, with the consequentreduction of the temperature of the circulated air and of the dew pointthereof. Next, the circulated air encounters the heating coil 74, aspreviously noted, whereby only sensible heat is supplied thereto, withthe consequent increase of the temperature of the circulated air withoutalteration of the dew point thereof; whereby the circulated airdelivered into the third conduit 13 is normally somewhat cooler and isexceedingly much drier than is the ambient air that is supplied to thefirst conduit 11.

Considering now the general mode of operation of the apparatus 10 in thenight cycle of operation, as enforced by the control circuit 200, theseven solenoids 658, etc., are energized, with the result that thetwoposition valve mechanisms 31, 80 and 110 occupy their operatedpositions; whereby the air that is supplied by the fan 51 into the firstconduit 11 proceeds from left to right through the housing 21 and thencethrough the second conduit 12 and through the housing 41 into the thirdconduit 13. The air in passing from left to right through the housing21, first encounters the secondary cooling coil 101 and then the primarycooling coil 71 and then the secondary cooling coil 102. Also, the brineis circulated from the pump 77 through the heating coil 74 and thencethrough the primary cooling coil 71 from right to left and thence backto the circulating pump 77. Furthermore, at this time, the pump 142effects circulation of the brine through the heat exchange coil 141 andthence through the secondary cooling coil 102 from right to left andthence back to the circulating pump 142. At this time, in the eventthere is an accumulation of frost upon the secondary cooling coil 101(resulting from the prior day cycle of operation of the apparatus 10),the frost mentioned is melted therefrom and is drained to the exteriorof the housing 21 in any suitable manner, not shown. This contact of thecirculated air with the secondary cooling coil 101 effects slightcooling thereof and possibly also some increase in the relative humiditythereof; however. these effects are not substantial and it may beassumed that the air passing into the port 24 in the left-hand end ofthe housing 21 is already at the ambient temperature and fullysaturated. The air next encounters the primary cooling coil 71, aspreviously noted, whereby both sensible heat and latent heat are removedtherefrom, with the consequent reduction of the temperature of thecirculated air and of the dew point thereof. The air next encounters theprimary cooling coil 102, as previously noted, whereby both sensibleheat and latent heat are removed therefrom, with the consequentreduction of the temperature of the circulated air and of the dew pointereof. Next, the circulated air encounters the heating coil 74, aspreviously noted, whereby only sensible heat is supplied thereto, withthe consequent increase of the temperature of the circulated air withoutalteration of the dew point thereof, whereby the circulated airdelivered into the third conduit 13 is normally somewhat cooler and isexceedingly much drier than is the ambient air that is supplied to thefirst conduit 11.

In view of the foregoing, it will be understood that either in the daycycle or in the night cycle of operation of the apparatus 10, the firstencounter of the circulated air with one of the secondary cooling coils101 or 102 that is not in operation is for the fundamental purpose ofdefrosting the secondary cooling coil mentioned. Moreover, either in theday cycle or in the night cycle of operation of the apparatus 10, thecirculated air is first cooled by the primary cooling coil 71 and isthen further cooled by the operating one of the secondary cooling coils101 or 102, and ultimately the circulated air is heated by the heatingcoil 74 before delivery to the third conduit 13. Also, it will beunderstood that the wet bulb device 46 is responsive to the dew point ofthe air delivered via the port 43 into the bottom of the housing 41;whereby the regulating valve 143 is correspondingly throttled so as toregulate the temperature of the operating one of the secondary coolingcoils 101 or 102, thereby to maintain substantially constant the dewpoint of the air delivered into the bottom of the housing 41.

Considering now a typical operating example of the apparatus 10: theambient air supplied by the fan 51 into the first conduit 11 may have atemperature of 70 F. and may be fully saturated. In passing over theprimary cooling coil 71, the temperature of the air may be reduced to575 F. and completely saturated. In passing over the operating one ofthe secondary cooling coils 101 or 102, the temperature of the air maybe reduced to 25 F. and completely saturated. In passing over theheating coil 74, the temperature of the air may be increased to 60 F.,with a dew point of 25 F. Accordingly, the conditioned air that issupplied via the third conduit 13 to the missile crib, or otherequipment making utilization thereof, has a temperature of 60 F. and adew point of 25 F.; whereby the dew point thereof is well below thefrost point (32 F.). Hence the ambient air at complete saturation isconditioned to the lower temperature (60 F.) and substantially dried (25F. dew point) prior to the supply thereof from the third conduit 13, asnoted above.

Furthermore, it will be understood that by virtue of the operation ofthe local heat-exchange circuit, including the primary cooling coil 71and the heating coil 74, both the sensible heat and the latent heat thatare extracted from the air in passing over the primary cooling coil 71are supplied as sensible heat to the air in passing over the heatingcoil 74. This arrangement contributes substantially to the efiiciency ofthe overall conditioning of the air by the apparatus 10. In the presentexample, 10,000 c.f.m. of ambient air may be conditioned by theapparatus 10 requiring a refrigerating capacity in the refrigeratingmachine of only 56 tons of refrigeration; on the other hand, the sameconditioning of 10,000 c.f.m. of the ambient air, utilizing only theoperating one of the secondary cooling coils 101 or 102 would require arefrigerating capacity in the refrigerating machine 130 of 90 tons ofrefrigeration.

In view of the foregoing, it is apparent that there has been providedapparatus for continuously conditioning air, both with respect to thetemperature. thereof and with respect to the relative humidity thereof,that requires no shut-down of any of the principal component elements ofthe apparatus and that requires no substantial duplexing of theprincipal component elements of the apparatus.

In the foregoing description, it is noted that the invention has beendescribed in conjunction with the conditioning of air, although the sameis equally applicable to the corresponding conditioning of other gases,such as natural gas, methane, ethane, etc.; whereby in the appendedclaims, the expression air should be deemed to cover not only air, butother such gases with respect to the corresponding conditioning thereof.

While there has been described what is at present considered to be thepreferred embodiment of the invention, it will be understood thatvarious modifications may be made therein, and it is intended to coverin the appended claims all such modifications as fall within the truespirit and scope of the invention.

What is claimed is:

1. Air conditioning apparatus comprising a first conduit, means forsupplying air into said first conduit, a second conduit, 2. firstelongated housing having first and second spaced-apart ports therein,means including a first two-position valve mechanism for selectivelyconnecting said first housing in opposite directions between said firstand second conduits, wherein the air flows from said first conduitthrough said first housing in a first direction from the first porttherein toward the second port therein and into said second conduit whensaid first valve mechanism occupies its first position and wherein theair flows from said first conduit through said first housing in a seconddirection from the second port therein toward the first port therein andinto said second conduit when said first valve mechanism occupies itssecond position, a third conduit, a second housing connected betweensaid second and third conduits, wherein the air flows from said secondconduit through said second housing into said third conduit, a primarycooler arranged in the intermediate portion of said first housing, aheater arranged in said second housing, means for connecting saidprimary cooler and said heater in series relation to form a localheat-exchange circuit, a first secondary cooler arranged in said housingand disposed between said first port therein and said primary cooler, asecond secondary cooler arranged in said housing and disposed betweensaid second port therein and said primary cooler, whereby the airflowing through said first housing in said first direction encounterssaid second secondary cooler and then said primary cooler and ultimatelysaid first secondary cooler and whereby the air flowing through saidfirst housing in said second direction encounters said first secondarycooler and then said primary cooler and ultimately said second secondarycooler, means including a second two-position valve mechanism forselectively supplying a coolant to said first and second secondarycoolers, wherein the coolant is supplied to said first secondary coolerwhen said second valve mechanism occupies its first position and whereinthe coolant is supplied to said second secondary cooler when said secondvalve mechanism occupies'its second position, and control means having afirst condition for simultaneously operating said valve mechanisms intotheir first positions and having a second condition for simultaneouslyoperating said valve mechanisms into their second positions.

2. Air conditioning apparatus comprising a first conduit, means forsupplying air into said first conduit, a second conduit, a firstelongated housing having first and second spaced-apart ports therein,means including a first two-position valve mechanism for selectivelyconnecting said first housing in opposite directions between said firstand second conduits, wherein the air flows from said first conduitthrough said first housing in a first direction from the first porttherein toward the second port therein and into said second conduit whensaidfirst valve mechanism occupies its first position and wherein theair flows from said first conduit through said first housing in a seconddirection from the second port therein toward the first port therein andinto said second conduit when said first valve mechanism occupies itssecond position, a third conduit, a second housing connected betweensaid second and third conduits, wherein the air flows from said secondconduit through said second housing into said third conduit, a primarycooler arranged in the intermediate portion of said first housing andprovided with first and second fixtures, a heater arranged in saidsecond housing, means including a sec ond two-position valve mechanismfor selectively connecting said primary cooler in opposite directions inseries relation with said heater to form a local heatexchange circuitcontaining a first coolant, wherein the first coolant is circulated fromsaid heater through said primary cooler in a first direction from thefirst fixture thereof toward the second fixture thereof and back intosaid heater when said second valve mechanism occupies its first positionand wherein the first coolant is circulated from said heater throughsaid primary cooler in a second direction from the second fixturethereof toward the first fixture thereof and back into said heater whensaid second valve mechanism occupies its second position,

a first secondary cooler arranged in said housing and disposed betweensaid first port therein and said primary cooler, a second secondarycooler arranged in said housing and disposed between said second porttherein and said primary cooler, whereby the air flowing through saidfirst housing in said first direction encounters said second secondarycooler and then said primary cooler and ultimately said first secondarycooler and whereby the air flowing through said first housing in saidsecond direction encounters said first secondary cooler and then saidprimary cooler and ultimately said second secondary cooler, meansincluding a third two-position valve mechanism for selectively supplyinga second coolant to said first and second secondary coolers, wherein thesecond coolant is supplied to said first secondary cooler when saidthird valve mechanism occupies its first position and wherein the secondcoolant is supplied to said second secondary cooler when said thirdvalve mechanism occupies its second position, and control means having afirst condition for simultaneously operating said valve mechanisms intotheir first positions and having a second condition for simultaneouslyoperating said valve mechanisms into their second positions.

3. The air conditioning apparatus set forth in claim 1, and furthercomprising means responsive to the dew point of the air flowing intosaid second housing for selectively regulating the coolant that issupplied to the one of said secondary coolers as established by theposition of said second valve mechanism.

4. The air conditioning apparatus set forth in claim 1,

and further comprising timing means for selectively opcrating saidcontrol means between its first and second conditions upon apredetermined time schedule.

5. The air conditioning apparatus set forth in claim 1, and furthercomprising a first device controlled by the formation of an undue amountof frost upon said first secondary cooler for operating said controlmeans from its first condition into its second condition, and a seconddevice controlled by the formation of an undue amount of frost upon saidsecond secondary cooler for operating said control means from its secondcondition into its first condition.

6. The air conditioning apparatus as set forth in claim 1, wherein saidprimary cooler extracts both sensible heat and latent heat from the airflowing through said first 7 housing, wherein said heater suppliessensible heat to the air flowing through said second housing, andwherein the total heat extracted by said primary cooler is substantiallyequal to the total heat supplied by said heater.

7. The air conditioning apparatus set forth in claim 1, wherein saidfirst secondary cooler is in a cooling phase and said second secondarycooler is in a defrosting phase when said second valve mechanismoccupies its first position, and wherein said first secondary cooler isin a defrosting phase and said second secondary cooler is in a coolingphase when said second valve mechanism occupies its second position.

8. The air conditioning apparatus set forth in claim 1, wherein saidprimary cooler extracts both initial sensible heat and initial latentheat from the air flowing through said first housing, wherein the one ofsaid secondary coolers as established by the position of said secondvalve mechanism extracts additional sensible heat and additional latentheat from the air flowing through said first housing, and wherein saidheater supplies sensible heat to the air passing through said secondhousing without increasing the dew point thereof.

9. The air conditioning apparatus set forth in claim 1, wherein the airsupplied into said first conduit is sub stantially at ambienttemperature and is substantially 12 completely saturated, and whereinthe air supplied into said third conduit has a temperature below theambient and a dew point below the frost point.

10. The air conditioning apparatus set forth in claim 1, wherein saidfirst two-position valve mechanism essentially comprises a casinghousing a rotatably mounted valve element having first and secondpositions, said casing communicating with said first and second conduitsand also with said first and second ports provided in said firsthousing, wherein rotation of said valve element into its first positionconnects said first conduit to the first port in said first housing andconnects said second conduit to the second port in said first housing,and wherein rotation of said valve element into its second positionconnects said first conduit to the second port in said first housing andconnects said second conduit to the first port in said first housing.

References Cited in the file of this patent UNITED STATES PATENTS2,445,705 Weinstein July 20, 1948 2,500,695 McGrath Mar. 14, 19502,522,484 Fingquist Sept. 12, 1950

